Synchronization of individual stations within a distributed network is an important issue for the wireless networking community. Synchronization is where individual stations within a network share the same concept of time. Synchronization is important in applications such as time-stamping and coordinating activities. Typically, the time kept by one station is broadcast to the other stations. Such broadcasts expend energy and make the network prone to error and susceptible to manipulation by unauthorized persons. Furthermore, clocks are imperfect and transmission delays only add to the problem. Therefore, there is a need for a method of synchronization that does not require broadcasts.
U.S. Pat. No. 6,665,541, entitled “METHODS AND APPARATUSES FOR USING MOBILE GPS RECEIVERS TO SYNCHRONIZE BASESTATIONS IN CELLULAR NETWORKS,” discloses a device for and method of synchronization that relies on broadcasts from the Global Positioning System (GPS). The present invention does not require a broadcast from the GPS for synchronization as does U.S. Pat. No. 6,665,541. U.S. Pat. No. 6,665,541 is hereby incorporated by reference into the specification of the present invention.
U.S. Pat. No. 6,813,324, entitled “SYNCHRONIZED COMMUNICATION SYSTEM,” discloses a device that includes a transmitter for transmitting a low frequency synchronization signal. The present invention does not transmit a low frequency signal to achieve synchronization as does U.S. Pat. No. 6,813,324. U.S. Pat. No. 6,813,324 is hereby incorporated by reference into the specification of the present invention.
U.S. Pat. No. 6,836,851, entitled “TWO-STEP SYNCHRONIZATION METHOD IN WHICH TWO MODULES ARE SYNCHRONIZED FIRST BY FREQUENCY FOLLOWED BY A SYNCHRONIZATION IN PHASE,” discloses a method of synchronization that requires two transmissions, one from a first station to a second station of the first station's clock signal, and one from the second station to the first station of its clock signal which was generated using the clock signal received from the first station. The present invention does not require two transmissions between two stations as does U.S. Pat. No. 6,836,851. U.S. Pat. No. 6,836,851 is hereby incorporated by reference into the specification of the present invention.